Coupling



E. J. WRAY July 15, 1958 COUPLING Filed Jan. 11, 1954 J W a a ornc ate

COUPLWG Edward John Wray, Barrie, Gntario, Canada, assignor to Canadian General Electric (Jornpany, Limited, Toronto, Ontario, Canada, a. corporation of Canada Application January 11, 1954, Serial No. 403,355

2 Claims. ((Il. 287-53) This invention relates to devices for mounting and retaining rotary tools on drive shafts.

in machines such as floor polishers where a tool is to be used for working on a continuous surface it is neces sary that the tool be mounted, in driving relation, at the end of the drive shaft. In the event that various operations are to be performed by the machine or in the event that the working tool is expendable it is desirable that the tool should be conveniently exchangeable and particularly in the case of household appliances that the removal of the tool should not require any additional implements or small parts which are easily lost. It is also a requirement that tools for rotation at relatively high speed should be well balanced about their center of rotation.

It is therefore an object of this invention to provide a mounting device for a rotating tool which facilitates its attachment to or removal from its driving shaft without the use of tools.

It is a further object of this invention to provide a mounting device for a rotary tool of convenient and economical construction having no loose parts which may be separated and misplaced.

It is also an object of this invention to provide a mounting device for a rotating tool which tends to maintain the tool automatically centered. Further objects and advantages may be ascertained from the following description and drawings of one specific example of my invention.

Fig. l is an illustration chiefly in section of my invention as applied to a floor polishing brush.

Fig. 2 is an illustration also in section of certain portions of Fig. 1.

Fig. 3 is a plan view of the portions shown in Fig. 2.

Referring to Fig. 1, I have shown my invention in conjunction with a floor polisher 1, a portion of which is shown with a driven vertical shaft 2 to the lower end of which is detachably secured in driving relation a polishing brush 3. The back of the brush 3 which is usually made of wood has centrally secured thereto by screws 6 a coupling member shown in more detail in Fig. 2. In Fig. 2 the coupling member is shown disassociated from the brush and polisher with only a small section of shaft 2.

This coupling member is formed from a single sheet of steel by stamping. An annular flange portion 4 is provided with holes 5 for mounting and a tubular central extension 8. This section 3 is then distorted until it is polygonal in cross section over a portion of its length adjacent the flange 4. This section is designated 7 and the sides of polygon 7 are approximately tangent to the circular section 8 as may be seen in Fig. 3. The end of tubular section 8 is flared slightly as illustrated at 9 in Fig. 2. The vertical driving shaft 2 has on its end a polygonal portion 10 which corresponds in dimensions to the inside dimensions of section 7 and a further extension 11 of circular cross section. Near the end of section ill is a groove 12 and retained in this groove is a 6 spring 13 of circular cross section and of such dimension as to be freely movable yet retained by the groove. As may be seen in Fig. 3 the expanded external diameter of the 0 spring is greater than the internal diameter of section 8 but the internal diameter is not as great as to permit the C spring to fall out of groove 9.

When the tool is mounted on the shaft the 0 spring is compressed as it passes through the tubular section 8 of the coupling member retreating into the groove 12 and then expanding as it reaches the flared portion d thus retaining the tool and the shaft in assembled relation and ensuring that the hexagonal portion 10 of the shaft is retained in driving relation with the hexagonal portion 7 of the coupling member.

The driving force is transmitted solely by the interengagement of sections 7 and 10 and not by the retaining spring 13. The spring 13 exerts a relatively uniform outward force and the coupling member is therefore maintained normally centered on its driving shaft. There is not normally any eccentric force tending to unbalance the system.

in removing the brush the reverse action takes place, a pull on the brush compresses the spring 13 sufficiently for it to pass through section 8 and the tool is then free. It will be noted that there are no parts which may be lost when the tool is removed, nor does the mounting or removal of the tool require special tools. This is particularly advantageous in household appliances.

It is now apparent that by my invention, I provide a simple and easily constructed mounting device for rotating'tools which tends to maintain the tool in its proper driving relation to its shaft and centered thereon.

It is also apparent that modifications could be made in this construction without differing from the spirit of my invention. For example, the polygonal section could be square rather than hexagonal. It is, therefore, my intention that the appended claims shall cover such moditications and applications as do not depart from the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A coupling for a driving member and a driven member which are adapted to rotate in unison at a high speed, said driven member being of such weight as to be subject to rotary unbalance with respect to the driving member at its normal operating speed, said coupling comprising a socket and a shaft, said socket including a tubular section having a portion of non-circular crosssection and an adjacent portion of circular cross-section, said circular portion being approximately tangent to the sides of said non-circular portion and terminating in a radially outwardly flared end portion, said shaft comprising a portion of corresponding cross-section to that of said non-circular portion and an end portion of corresponding cross-section to that of said circular portion, said shaft end portion having an annular groove formed near its end, and a resilient C-shaped spring mounted in and having a portion thereof extending out of said groove, the dimensions of the cooperating portions of said socket and said shaft being such that when said shaft is inserted fully into said socket, said C-shaped spring is disposed adjacent to and contacts said flared end portion of said socket, whereby said spring securely couples said socket and said shaft together in such a shaft at its normal operating speed, said coupling comprising a unitary stamped metal member having a flange portion for mounting said member to said tool and a tubular section, the portion of said section adjacent to said flange being non-circular, said section having a circuit portion adjacent to said non-circular portion and approximately tangent to the sides of said non-circular portion, said circular portion terminating in a radially outwardly flared end portion, said shaft having portions corresponding to said circular and said non-circular por- 4 tions of said section and supporting resilient means at its end which is adapted to contact said flared end portion When said shaft is inserted fully into said tubular section to thereby couple said tool to said member.

References Cited in the file of this patent UNITED STATES PATENTS 1,422,067 Abegg July 11, 1922 2,429,782 Versoy Oct. 28, 1947 2,523,041 McKenzie Sept. 19, 1950 

